Conveyer roller



Nov. 29, 1932. E. DREXLER CONVEYER ROLLER Filed Nov. 10, 1928 2 Sheets-Sheet 1 644 E/LLXINVENTOR A TTORNEY.

Nov. 29, 1932. DREXLER 1,889,173

CONVEYER ROLLER Filed Nov. 10, 1928 2 Sheets-Sheet 2 '17 Z! 14 15 25 J IZ a I Y H 17 INVENTOR.

ATTORNEY.

Patented Nov. 29, 1932 UNITED STATES PATENT OFFICE ERNEST DREXLER, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR T SCHLOEMANN ENGINEERING COMPANY, OF PITTSBURGH, PENNSYLVANIA V GONV'EYER ROLLER Application filed. November 10, 1928. Serial No. 318,532.

My invention relates to motor-driven conveyer rollers adapted to be driven singly, independent of the adjacent rollers.

The old method of driving conveyer rollers in multiple units by the rollers being geared to a common source of power, has gradually been abandoned because of the difficulties and cost of installation and because of the small amount of flexibility, and therefore,

motors have been directly coupled with such conveyerrollers. In order to avoid, however, the special foundations and save the extra space required for the operating motor, the electric motor has been directly incorporated in the conveying roller, but this required a departure from standard designs and in fact a revolutionary change in the manufacturing plants of electric motors.

Now, in accordance with this invention, the electric elements are incorporated in the conveyer rollers without the component parts of the electric motor being essentially changed and without any special'foundations being required, while the motor part is completely protectedby the roller. Moreover, the arising mechanical stresses are balancedand torsional stresses in the shafts are avoided. Finally, the cost ofmaintenanceand repairs is small. For a complete understanding of the invention, I refer to the accompanying drawings, in which, by way of illustration, I have shown various embodiments of the invention, and in which Fig. 1 is a central longitudinal sectional View through one embodiment, Fig.

2 a transverse section along line 22 in Fig. 1, Fig. 3 a similar view as Fig. 1 showing a modified embodiment, Fig. 4: a transverse section along line 44 in Fig. 3, Fig. 5 a simi- 450 lar view as Fig. 1, showing yet another modification, Fig. 6 a transverse section along line 6-45 in Fig. 5, Fig. 7a similar view as Fig. 1 showing a further modification, and Fig. 8 a transverse section along line 8-8 in Fig. 7. In conveyer systems comprising a series of independent conveyer rollers, the latter are ordinarily aligned in rows, the shafts being substantially parallel, the supporting means for the rollers extending on either side in the direction of the alignment of the rollers.

These supporting means are shown in the drawings as channel irons 9 and 10. Upon these channel irons rest the roller frames 11. Brackets 12 forming parts of said frames extend upwards on both sides thereof. In saidbrackets are mounted ball bearings 13 which are held in position by bearing ca s 14. Said ball bearings rotatively support t 1e main shaft 15 of the conveyer roller, shown at '16 and substantially consisting of a cylin drical shell provided with an end wall having a hub-like extension, whereby said shell is mounted on shaft 15 being secured thereto by key 17 In the embodiments shown in Figs. 1 and 3 the roller 16 isadditionally supported on shaft 15 .by a flanged disk 18 makingthe roller a closed hollow drum. Inside the shell is provided the electric motor.

In theembodiments show in Figs. 5 and 7 the motor is of the present day polyphase induction-type design. In the housing 19 of this motor is mounted the stator or field, comprising the-laminated core 20 and the stator coils 21, which are connected through an opening 22 in the housing by wires 23 to a source of electric power. Within the stator, is located the induction-type rotor, comprising thelaminated core2 l and the short-circuiting circuit 25, and mounted on shaft 15. In Figs. 1 and 3 the parts of the motor are shown in the reverse arrangement, the stator comprising the laminated core 26, and the short-circuiting circuit 27 being the inductive part. The rotor which is mounted on shaft 15, comprises the laminated core 28 and the windings 29, from which wires 30 lead to a source of electric power. The wires extend through a bore 31 in shaft 15 to concentric slip-rings 82, 33, 34 on the end of the shaft (Fig. 1). These slip-rings are insulatedly mounted on the end of shaft 15, and brushes 85, 36 and 37 insulatedly mounted on a cap 38 covering the end of bracket 12 transmit electric current to said slip-rings. In Fig. 3, three slip-rings 39 are insulatedly mounted, adjacent to each other, on the cylindrical end of shaft 15, and brushes 40, insulatedly mounted on a cap 41 in this instance serve as steps for transmitting electro-motive power to the windings on the rotor.

According to Figs. 1, 3 and 5 the substantially closed housing 19 of the motor carries at both ends the outer race ring of a ball hearing 42, the inner race ring being provided on shaft 15.

In the embodiment shown in Fig. 1 a weight 44 is provided on the bottom of the motor housing 19 being made integral therewith. The mass of this weight is substan tially such that it prevents rotation of the housing when the maximum starting torque is exerted in the rotor.

In the modification shown in Fig. 3 the weight indicated at 45 constitutes the arma ture of a magnet, which is located in the electro-magnetio field of the electro-magnet 46 mounted in asuitable clearance space of frame 11. The ends 47 of the poles of said electro-magnet being concave are concentrically disposed close to the shell of the conveyer roller 16. The air gaps between the poles ofthe electro-magnet and the'outside of said shell and between the armature 45 and the inside of said shell are made as small as possible, and the material of said shell is highly permeable andformed as thin as possible so as to offer 'a low resistance to the magneticflux. Wires 48 supply electric current,preferablyd irect current,for the electromagnet 46.

In the modification shown in Figs. 3 and 4, the weight of the armature on the motor housing 19 combined with the electro-magnetic force exerted by the velectro-magnet upon said armature, is chosen of a magni tude s'uflicient to overcome the maximum torqueof the motor. If direct current is used for the electro-magnet, polarized segments may take the place of the laminations 40 of the armature 45. Inthat case, the electromagnet may have, as a core, a permanent magnet so that only the amount of electricity necessary to maintain a maximum flux in the magnet has to be introduced into the winding 48. v

The shell of conveyer roller 16 is. open on the left hand end in the modification shown in Fig. 5, and rollers contained in cages 49 are provided to support the shell of con- 50 fully excited and shaft 15 is at rest.

In the modification shown in Fig.7, the

bearings 42 shown in the other embodiments for rotatively supporting the motorhousing on shaft 15 are entirely dispensed with. A

cap 52 with clearance openings for shaft 15 and for the electric wires 23 extends over one end of the motor protecting that end, the corresponding end of the shell of conveyer roller 16 being open. There is a strong extension 53 on the frame 11 projecting into the inside of the shell of conveyer roller 16 and supporting the housing 19 of the motor.

The operation is substantially the same for all modifications shown:

In each case, the main shaft, the conveyer roller and the rotor part of the motor substantially form a rotatable unit, and in each case I have shown means for retaining the motor housing together with the stator stationarily, in a position so as to electromotive- 1y drive the rotor, and, therefore, said unit, there being no engagement between said housing and any parts of said rotatable unit.

In the drawings, which is for illustration only, the important and active part, e. g. bearings and hubs are shown of enlarged dimensions as compared with those of the rotor, stator, motor housing and conveyer roller, in the direction of the axis of the shaft. The hubs of the conveyer roller, the bearings of the motor housing and the bearings supporting shaft 15 being disposed in close proximity to each other at either end of the conveyer roller, shaft 15 is practically free from unbalanced stresses. It will also be seen that the double enclosure of the motor by the motor housing as well as by the roller shell affords increased protection against injury as well as against dirt. roller can be readily taken out of the frame by the simple expedient of the removal of the bearing caps, 13, whereupon the roller can be lifted out.

While I have shown various embodiments of my invention, it will be appreciated that it is capable of various modifications. For instance, other means than those shown, may be used for retaining the stator and housing in a fixed position and therefore I do, of course, not limit myself to the embodiments of my invention herein shown and described.

I claim 1. A conveyer roller comprising a stationary frame, a shaft journaled for rotation in said frame, a hollow shell fixed to said shaft, an electric motor within said shell inclusive of a stator and a rotor, the stator being hollow and the rotor being disposed within the stator and fixed to said. shaft, and substan tially stationary means independent of any other element adapted to hold the stator against rotation.

2. A conveyer roller as set forth in claim 1 in which the means for holding the stator against rotation comprises a weight fixed with respect to the stator.

3. A conveyer roller as set forth in claim 1 in which the means for holding the stator against rotation comprises a weighted motor Furthermore, the conveyer housing Within the shell having the stator fixed thereto.

4- A conveyor roller as set forth in claim 1 in Which the means for holding the stator against rotation comprises an electro-magnet.

In testimony whereof I aifix my signature.

ERNEST DREXLER. 

